JP6997250B2 - dam - Google Patents

Description

The present invention relates to a dam installed in a river or the like.

In rivers such as mountainous areas, dams are installed to prevent sediment-related disasters caused by typhoons and heavy rains (see, for example, Patent Document 1). The dam prevents the passage of rocks and driftwood contained in the debris flow while allowing water to pass through, and at the wall of the dam, it weakens the momentum of the debris flow and also works to block the rocks and driftwood. In recent years, in order to capture only rocks and driftwood without blocking the passage of water, a slit is formed in a part of the dam, and a trapping body constructed in a fence shape with a steel pipe or the like is provided in this slit, so-called permeation. A type dam is constructed (see, for example, Patent Document 2).

In recent years, in order to suppress damage caused by sediment-related disasters, attempts have been made to newly install a catching body in the water passage part of an existing dam that is not provided with a catching body. As shown in FIG. 10, in order to provide the capture body 103 with respect to the existing dam 100, it is necessary to raise the sleeve portion 105 around the capture body 103 in order to secure the water passage portion 104. By raising the circumference of the catching body 103, as shown in FIG. 11, the catching body 103 can catch the driftwood and the like 106, and the space formed above the driftwood can be used as the water passage portion 107.
Further, as shown in FIG. 12, when the catching body 111 is provided on the existing dam 110 having a short floor width (width along the flow direction of the river), the upstream side or the downstream side of the water passage portion 112 of the dam 110. The abdominal portion 113 is provided in the abdomen portion 113, and the trapping body 111 is provided by utilizing the bottom portion of the water passage portion 112 and the abdominal portion 113.

Special Fair 2-55566 Gazette Japanese Unexamined Patent Publication No. 2015-63840

However, if the dam is raised, the external force of the debris flow acting on the wall will also increase, so the strength of the dam will be insufficient, and improvement work to eliminate the lack of strength will take cost and time.
In addition, in a so-called impermeable dam that is not provided with a catcher, the width of the water passage portion is narrow in order to control the flow of water, so the catcher provided in the water passage portion becomes smaller, and the eyes are immediately noticed. It becomes clogged and easily overflows from the sleeve of the dam. As a result, not only the function of capturing driftwood and the like cannot be fully exerted, but also improvement work on the downstream side of the dam is required in preparation for overflow, which is costly and time-consuming. On the other hand, widening work of the water passage part is also conceivable, but this also costs money and time.
In addition, even if the abdomen is provided on the dam, the construction will be costly and time consuming.
In addition, in order to newly fix the catching body to the existing dam, the concrete for the catching body must be placed after the concrete of the water passage part is put in, so it takes cost and time to erection the scaffolding. Will end up.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a dam that can install a trapping body more easily than before and can reduce the cost and time required for construction.

In order to solve the above-mentioned problems, the present invention comprises a dam having a water passage portion, which is provided on the wall surface on the upstream side of the dam and has a catching body for catching driftwood flowing from the upstream and passing water through the dam. The trap is characterized in that at least a part of the trap is provided at a position on the upstream side of the water passage portion, which is separated from the water passage portion and faces the water passage portion.

Further, it is preferable that the capture body is inclined to the upstream side as it goes upward.

Further, in the capture body, one end is fixed to the wall surface on the upstream side of the dam, and one end is fixed to the wall surface on the upstream side of the dam, and the other end is fixed to the first leg portion. It is preferable to include a plurality of pillar portions having a second leg portion connected to each other, and a beam portion connecting each pillar portion to each other.

Further, it is preferable that the first leg portion is inclined to the upstream side from one end toward the other end.

Further, it is preferable that the second leg is arranged along the slope of the ground on which the dam is installed.

Further, it is preferable that the other end of the first leg portion is above the bottom surface of the water passage portion.

Further, the length of the trapping body is preferably longer than the width of the water passage portion.

Further, it is preferable that the pillars are arranged at an interval corresponding to 1/2 of the maximum driftwood length or the maximum gravel diameter.

According to the present invention, the catching body can be installed more easily than before, and the cost and time required for construction can be suppressed.

(A) is a front view of the dam, and (b) is a side view of the dam. It is a front view of the dam seen from the upstream. It is a perspective view which looked at the dam from the upper right side. It is a perspective view which looked at the dam from the lower right side. It is a plan view of a dam. It is a side view of the dam explaining the state of the trapping body when the earth and sand are accumulated on the upstream side of the dam. In the swept section of a river, (a) is a front view of a dam that captures driftwood and allows water to pass through, (b) is a side view of the dam, and (c) is a side view of the dam. It is a plan view. In the debris flow section of a river, (a) is a front view of a dam that captures driftwood and earth and sand and allows water to pass through, (b) is a side view of the dam, and (c) is the dam. It is a plan view of. (A) is a front view of the dam according to the modified example seen from the upstream, and (b) is a perspective view of the dam according to the modified example seen from the upper right side. In the prior art, (a) is a front view of the dam illustrating a method of raising the dam to provide a trap, and (b) is a side view of the dam. In the prior art, (a) is a front view of a dam for explaining a state in which driftwood is captured and water is allowed to pass through the dam of FIG. 9, and (b) is a side view of the dam. It is a side view of the dam explaining the state which provided the abdominal part for providing the trapping body in the dam in the prior art.

A preferred embodiment of the present invention will be described with reference to the drawings. In addition, the embodiment shown below is an example, and various forms can be taken within the scope of the present invention.

<Structure of dam>
As shown in FIG. 1, the dam 1 includes a main body 2 and a trapping body 3. The dam 1 is an existing main body 2 already installed in a river, and a catching body 3 is newly installed to enhance the catching function of driftwood and rocks.

(Main body)
As shown in FIG. 1, the bottom of the main body 2 is buried in the ground, and is constructed so as to extend along the width direction of the river so as to cross the river. The main body 2 is constructed of, for example, concrete or soil cement. In the main body 2, the wall surface facing the upstream side or the downstream side of the river may be a steel plate wall formed by connecting a plurality of steel segments, and the inside thereof may be filled with concrete or soil cement.
At the upper end of the main body 2 near the center along the width direction of the river, a water passage portion 21 cut out (recessed) so that the upper end is lower than the surroundings is formed. The water passage portion 21 is formed to collect the flowing water flowing from the upstream in the vicinity of the center of the main body 2 and to flow the water downstream.
The main body 2 includes an upstream wall portion 22 facing the upstream side of the river and a downstream wall portion 23 facing the downstream side of the river. The upstream wall portion 22 is inclined toward the upstream side as it goes downward from the bottom surface of the water passage portion 21. The downstream wall portion 23 is inclined toward the downstream side as it goes downward from the bottom surface of the water passage portion 21.

(Capture body)
As shown in FIGS. 1 to 5, the capture body 3 captures driftwood flowing from the upstream of the river and allows the flowing water to pass therethrough, and is provided on the upstream wall portion 22 of the main body 2. The capture body 3 is provided along the extending direction of the main body 2, that is, the width direction of the river. At least a part of the catching body 3 is provided at a position facing the water passage portion 21 at a position separated from the water passage portion 21 on the upstream side of the water passage portion 21. The capture body 3 is inclined to the upstream side as it goes upward. The catching body 3 is constructed so that the length L in the width direction is longer than the width W of the water passage portion 21. The capture body 3 is provided on the main body 2 so that at least a part thereof is located above the bottom surface of the water passage portion 21 of the main body 2.

The capture body 3 has one beam portion 31 extending along the width direction of the main body 2 (the width direction of the river) and a plurality of beam portions 31 connected at predetermined intervals along the extending direction of the beam portion 31. It is provided with a pillar portion 32.
The beam portion 31 and the column portion 32 are formed of, for example, steel pipes. The pillar portion 32 includes a first leg portion 32a and a second leg portion 32b.
One end (lower end) of the first leg portion 32a is fixed to the upstream wall portion 22 of the main body 2 by anchor bolts and nuts. The first leg portion 32a is connected to the beam portion 31 at the other end (upper end). As a result, each column portion 32 is connected by the beam portion 31. The first leg portion 32a is provided on the upstream wall portion 22 so as to incline toward the upstream side from one end fixed to the upstream wall portion 22 toward the other end.
One end of the second leg portion 32b is fixed to the upstream wall portion 22 of the main body 2 by anchor bolts and nuts. The second leg portion 32b is connected to the central portion in the longitudinal direction of the first leg portion 32a at the other end. Here, if the second leg portion 32b is arranged along the slope of the riverbed on the upstream side, the force of the debris flow can be received along the axial direction of the second leg portion 32b. It is preferable because the force that the leg portion 32b of 2 tries to peel off from the upstream wall portion 22 of the main body 2 can be suppressed to a small extent. As a result, the pillar portion 32 is constructed in a substantially λ-shaped side view, and the first leg portion 32a is longer than the second leg portion 32b.
The distance S between adjacent pillars 32 is half the length of the maximum driftwood expected to flow through the river, or the length corresponding to the maximum gravel diameter expected to flow through the river. It is preferable that it is a pebbles.

<How to install the capture body>
Next, a method of installing the capture body 3 when the capture body 3 is provided on the main body 2 of the existing dam to construct the dam 1 will be described.
First, the installation position of the capture body 3 on the upstream wall portion 22 of the main body 2 is drilled, an anchor bolt is embedded in the formed hole, and mortar or the like is filled in the hole and fixed.
Next, the flange portions provided at one ends of the first leg portion 32a and the second leg portion 32b are passed through the anchor bolts and fixed with nuts. Here, in the capture body 3, the beam portion 31 and the pillar portion 32, each of which is made of a steel pipe, are joined in advance by welding or the like, and are fixed with nuts while being suspended by a crane or the like. Here, it is preferable that the length of the capture body 3 (the length of the beam portion 31) is at least longer than the width of the water passage portion 21 of the main body 2.
When the capture body 3 is provided on the main body 2, the capture body 3 is attached to the main body 2 so that a part of the capture body 3 is located above the bottom surface of the water passage portion 21 of the main body 2.
Through the above steps, the trapping body 3 can be installed on the main body 2 of the existing dam, and the dam 1 having an enhanced catching function for driftwood and the like of the existing dam is constructed.

As described above, by providing the catching body 3 on the upstream wall portion 22 of the main body 2 of the existing dam, the function of catching driftwood, earth and sand, etc. can be added, the function as the dam 1 is improved, and the earth and sand are improved. Disasters can be suppressed.
Further, since the trapping body 3 can be provided in the main body 2 in advance assuming the occurrence of debris flow due to a typhoon or heavy rain, it is possible to prevent sediment-related disasters.
Further, since the first leg portion 32a of the capture body 3 is inclined to the upstream side as it goes upward, the driftwood and boulder that have flowed toward the lower side of the dam 1 along the first leg portion 32a. It is possible to further enhance the effect of preventing overflow of driftwood and the like.
Further, since the trapping body 3 is arranged so as to project above the bottom surface of the water passage portion 21, as shown in FIG. 6, sediment is accumulated on the upstream side of the dam 1 after many years have passed. Even if it is done, it is possible to maintain the capture function of driftwood and the like.
Further, since the capture body 3 is provided so that the portion facing the water passage portion 21 is separated from the water passage portion 21, it is possible to capture the driftwood or the like before the driftwood or the like flows into the water passage portion 21.
Further, since the second leg portion 32b is arranged along the slope of the ground (river bottom) where the dam 1 is installed, the collision energy of driftwood or the like transmitted from the first leg portion 32a is transmitted along the axial direction. Since it can be received, the force that the second leg portion 32b tends to peel off from the main body 2 can be minimized.
Further, since the length of the capture body 3 is longer than the width of the water passage portion 21, most of the driftwood and the like can be captured before the driftwood and the like flow into the water passage portion 21.

Here, if the capture body 3 is provided in the existing water passage portion 21, it is necessary to raise the dam body in order to provide a new water passage portion. However, in the dam 1, the capture body 3 is the upstream wall portion 22. Since it is provided so as to be separated from the water passage portion 21, it is not necessary to raise the main body 2 and improvement work for solving the insufficient strength of the dam 1 is not required.
In addition, since it is not necessary to perform improvement work on the downstream side of the dam 1, widening work of the water passage portion 21, and abdominal work in preparation for overflow from the main body 2, the construction cost should be reduced and the construction period should be shortened. Can be done.
Further, in order to raise the height of the main body 2 and install the catching body 3, it is not necessary to pour the concrete of the water passage portion 21 and then cast the concrete for fixing the catching body 3, and the existing main body 2 is significantly reduced. No need to improve.
Therefore, the catching body 3 can be installed on the main body 2 more easily than before, and the construction cost can be reduced and the construction period can be shortened.

Here, if the installation location of the dam 1 is a swept section of a river, as shown in FIG. 7, only the driftwood 41 is captured by the capture body 3, and the flowing water 42 passes through the capture body 3 and the water passage portion 21. Guided by. As a result, the driftwood 41 is deposited in the opening of the water passage portion 21 to obstruct the flow of water, and it is possible to prevent the overflow from the sleeve portion of the main body 2 due to the increase in the water volume, and it is necessary to raise the dam 1. Is gone. Therefore, the capture body 3 can be installed so that the driftwood 41 can be effectively captured without modifying the existing dam, and the cost and time required for the construction can be suppressed.

On the other hand, if the installation location of the dam 1 is a debris flow section of a river, as shown in FIG. 8, the catching body 3 catches the driftwood 41 and the earth and sand 43, and the flowing water 42 passes through the catching body 3 and the water passage portion 21. Guided by. As a result, the driftwood 41 and the earth and sand 43 are accumulated in the opening of the water passage portion 21 to obstruct the flow of water, and it is possible to prevent the overflow from the sleeve portion of the main body 2 due to the increase in the water volume, and the dam 1 can be formed. There is no need to raise it. Therefore, the capture body 3 can be installed so that the driftwood 41 and the earth and sand 43 can be effectively captured without modifying the existing dam, and the cost and time required for the construction can be suppressed.

<Others>
The present invention is not limited to the above embodiment. For example, the structure of the catcher can be freely changed as long as it has a function of catching driftwood and boulders. Further, the method of fixing the capture body to the main body can be freely changed, and it may be arranged at a position satisfying the above-mentioned conditions.
Further, the capture body is not limited to the case where it is attached to an existing dam, and may be constructed together with the main body at the time of construction of the dam.

<Modification example>
Next, the dam 1A according to the modified example will be described with reference to FIG. In the following description, only the portion different from the dam 1 according to the above embodiment, particularly the capture body 5, will be described.
The catching body 5 is a single beam portion 51 extending along the width direction of the main body 2 (the width direction of the river), and a plurality of beam portions 51 connected at predetermined intervals along the extending direction of the beam portions 51. It is provided with a pillar portion 52.
The beam portion 51 and the column portion 52 are formed of, for example, steel pipes. The pillar portion 52 includes a first leg portion 52a and a second leg portion 52b. The distance S1 between the adjacent pillars 52 is half the length of the maximum driftwood expected to flow in the river, or half the length of the maximum driftwood expected to flow in the river, similar to the distance S between the pillars 32 in the above embodiment. It is preferable that the length corresponds to the maximum gravel diameter expected to flow through the river.
The beam portion 51 and the pillar portion 52 (first leg portion 52a, second leg portion 52b) of the capture body 5 have the same configuration as the beam portion 31 and the pillar portion 32 of the capture body 3, and thus are specific. I will omit the explanation about the configuration.
The catching body 5 is constructed so as to be longer than the width of the water passage portion 21, that is, the pillar portions 52 provided at both ends in the width direction (river width direction) of the catching body 5 are at least the main body. It is arranged at a position facing 2 on the side of the upstream wall portion 22. Specifically, in the catching body 5, three pillars 52 out of the pillars 52 on both ends in the width direction face (cover) the main body 2 on the side of the water passage portion 21 in the width direction. It is installed in. In other words, when the distance S1 between the pillar portion 52 and the pillar portion 52 is one span, the capture body 5 is constructed so as to face the main body 2 by two spans. Of the two spans facing the main body 2, one span on the water-permeable portion 21 side may be at least partially facing the main body 2.
Further, the range of the capture body 5 facing the main body 2 depends on, for example, the maximum length of driftwood expected to flow in the river, the maximum gravel diameter, the scale of the dam 1 to be installed, and the like. It can be appropriately changed so as to face the main body 2 by the amount of span, 3 spans or more.
As described above, the catching body 5 extending to the position facing the main body 2 in the width direction with respect to the water passage portion 21 expands the range for catching the driftwood and the boulder that has flowed in the width direction, and the driftwood and the boulder are widened. Can be effectively prevented from wrapping around from the side of the capture body 5.

1,1A Dam 2 Main body 3,5 Capturing body 21 Water passage part 31,51 Beam part 32,52 Pillar part 32a, 52a First leg part 32b, 52b Second leg part

Claims (5)

A dam with a water passage
It is attached to the wall surface on the upstream side of the dam, and is equipped with a catching body that catches driftwood flowing from the upstream and allows flowing water to pass through.
At least a part of the trap is provided at a position on the upstream side of the water passage portion, which is separated from the water passage portion and faces the water passage portion .
A dam characterized in that at least a portion of the trapping body facing the water passage portion is attached to a wall surface on the upstream side of the dam below the water passage portion . The capture body is
A first leg whose one end is fixed to the wall surface on the upstream side of the dam, and a second leg whose one end is fixed to the wall surface on the upstream side of the dam and the other end is connected to the first leg portion. With a plurality of pillars having a part,
The beam part that connects each pillar part and the beam part
The dam according to claim 1, wherein the dam is provided with. The dam according to claim 2 , wherein the first leg portion is inclined to the upstream side from one end to the other end. The dam according to claim 2 or 3 , wherein the second leg is arranged along an inclination of the ground on which the dam is installed. The dam according to any one of claims 1 to 4 , wherein the length of the trap is longer than the width of the water passage portion.

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